What the FDA labels say about taking them together
Diltiazem and efavirenz/lamivudine/tenofovir disoproxil
Efavirenz/lamivudine/tenofovir disoproxil's FDA label of October 15, 2019 names diltiazem in its drug interactions section; the diltiazem labels PlainMeds reads (4) do not name efavirenz/lamivudine/tenofovir disoproxil. The efavirenz/lamivudine/tenofovir disoproxil label: “Diltiazem dose adjustments should be guided by clinical response.”
Check it at the source: the diltiazem FDA label on DailyMed (effective August 7, 2026, Bausch Health US, LLC); the efavirenz/lamivudine/tenofovir disoproxil FDA label on DailyMed (effective October 15, 2019, Viatris Specialty LLC).
What does the diltiazem label say about efavirenz/lamivudine/tenofovir disoproxil?
Diltiazem's label (effective August 7, 2026) and its 3 other brand-application labels do not name efavirenz/lamivudine/tenofovir disoproxil in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (TIAZAC EXTENDED RELEASE), Bausch Health US, LLC, effective August 7, 2026 (SPL set c567fe7e-887e-4291-a0d1-2dd3f25cbf25), via openFDA; the full label on DailyMed
What does the efavirenz/lamivudine/tenofovir disoproxil label say about diltiazem?
Efavirenz/lamivudine/tenofovir disoproxil label, drug interactionsConcomitant Drug/Class/Drug Name: Calcium channel blockers: Diltiazem; Effect: ↓ diltiazem ↓ desacetyl diltiazem ↓ N-monodesmethyldiltiazem; Clinical Comment: Diltiazem dose adjustments should be guided by clinical response (refer to the full prescribing information for diltiazem).
Source: FDA drug label (SYMFI), NDA022142 (Mylan Labs Ltd), as published by Viatris Specialty LLC, effective October 15, 2019 (SPL set 81a55dd9-78a8-49c3-88ab-8f5bffafa359), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Diltiazem | Efavirenz/lamivudine/tenofovir disoproxil | |
|---|---|---|
| Labeled for | High blood pressure, Angina, Atrial fibrillation | HIV |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.144 per capsule 24h ER(cd) 120 mg capsule | n/a |
| Shortage now | A presentation being discontinued | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once